Device and method for producing transformer cores

ABSTRACT

The invention relates to a device and a method for producing transformer cores, the device comprising a cutting device (33) for cutting sheets of metal (16) from which a transformer core is constructed and comprising a reel system (32) having a reel (34, 35), the reel having reel heads (36, 38) each having steel-strip rolls (37, 39), at least one steel-strip roll being disposed so as to be able to be unwound in a production direction of the cutting device, a sheet-metal strip (42, 43) of the steel-strip roll being able to be supplied to the cutting device, the reel system comprising at least two reel heads each having a steel-strip roll disposed thereon, the steel-strip rolls being able to be unwound in the production direction of the cutting device and being disposed in a row relative to one another, the device having a supply system (46) by means of which sheet-metal ends of the sheet-metal strips of the steel-strip rolls being supplied to the cutting device in an automated manner.

The invention relates to a device and a method for producing transformer cores, the device comprising a cutting device for cutting sheets of metal from which a transformer core can be constructed and comprising a reel system having a reel, the reel having reel heads each having steel-strip rolls, at least one steel-strip roll being disposed so as to be able to be unwound in a production direction of the cutting device, a sheet-metal strip of the steel-strip roll being supplied to the cutting device.

The installations known from the state of the art for producing transformer cores are constructed according to a progress sequence in such a manner that sheets of metal for transformers first are cut from sheet-metal strips by means of a cutting device. The sheet-metal strips are stored on a steel-strip roll which is held by a reel head of a reel. The reel can have a plurality of reel heads having steel-strip rolls so that different sheet-metal strips of the cutting device can be supplied as required. The sheet-metal strips can be exchanged at or supplied to the cutting device manually or via a conveyor belt, for example; however, the exchange of the sheet-metal strip and/or the steel-strip roll requires much time.

The sheets of metal cut in the cutting device can have different geometries since a transformer core is often constructed from sheets of metal of different shapes. The sheets of metal can be guided away from the cutting device by a conveyor belt and be stored and/or stacked for further processing. The transformer core is constructed from the sheets of metal on a so-called stacking table. On the stacking table, threading bolts and/or sheet-metal abutments are mounted in a fixed manner as positioning aids and the sheets of metal are constructed and/or stacked on the threading bolts to form the transformer core. The sheets of metal in particular have bores and/or cutouts in which the threading bolts can engage. The sheets of metal are stacked on threading bolts and/or stacked along the sheet-metal abutments and thus accurately positioned in relation to one another. Sheets of metal can generally be stacked manually but also in an automated manner. It is essential that a sufficient number of different sheets of metal is made available at all times for constructing the transformer core so as to avoid standstills, for example.

Since the stacking table is always constructed for a transformer core having a position of the positioning aids and/or the threading bolts displaceable in guide rails, a stacking table can always only be used after retrofitting for producing one kind of transformer core. If different kinds of transformer cores are to be produced using one installation, a correspondingly large number of stacking tables is required for core shapes outside of the displacement ranges of the positioning aids which have to be held available.

The object of the invention at hand is therefore to propose a device and a method for producing transformer cores which both enable a cost-effective production of transformer cores.

This object is attained by a device having the features of claim 1 and a method having the features of claim 7.

The device according to the invention for producing transformer cores comprises a cutting device for cutting sheets of metal from which a transformer core can be constructed and comprises a reel system having a reel, the reel comprising reel heads each having steel-strip rolls, at least one steel-strip roll being disposed so as to be able to be unwound in a production direction of the cutting device, a sheet-metal strip of the steel-strip roll being able to be supplied to the cutting device, the reel system comprising at least two reel heads each having a steel-strip roll disposed thereon, the steel-strip rolls being disposed so as to be able to be unwound in the production direction of the cutting device and being disposed in a row relative to one another, the device comprising a supply system by means of which sheet-metal ends of the sheet-metal strips of the steel-strip rolls being able to be supplied to the cutting device in an automated manner.

The reel system comprising the two reel heads is therefore realized such that at least two steel-strip rolls are disposed so as to be able to be unwound and wound in the production direction of the cutting device at all times. These steel-strip rolls are consequently disposed in a row relative to one another in such a manner that the respective sheet-metal strips of the steel-strip rolls are alternatingly supplied to the cutting device. Using the supply system, one sheet-metal end of one of the sheet-metal strips can be supplied to or drawn from the cutting device in an automated manner. An optional supply of sheet-metal ends of the steel-strip roll is possible so that depending on which transformer sheet metal is to be produced by the cutting device, the respectively suitable sheet-metal strip can be introduced into a feeder, made up of rolls for example, of the cutting device by the supply system. If sheet-metal strips for producing other sheets of metal for a transformer are to be exchanged, the sheet-metal strip can be drawn from the cutting device by means of the respective reel head and be introduced into the feeder of the cutting device in an automated manner by means of the supply system of the sheet-metal strips intended for processing. All in all, it becomes possible to quickly exchange the sheet-metal strips to be processed without a laborious exchange of reel heads having steel-strip rolls upstream of the cutting device. Also, this exchange is not particularly complex as it can be carried out in an automated manner by means of the supply system. All in all, different transformer cores can be produced quicker and thus more cost-efficiently using the device.

The supply system can comprise a multiaxial robot. The robot can then comprise means for grappling sheet-metal ends so that a sheet-metal end can be collected from the steel-strip roll by the robot and be transported to a feeder of the cutting device. These means can be, for example, a vacuum exhauster, a magnet or pliers, which can be disposed optionally on one end of a robot arm of a multiaxial robot. A production of sheets of metal for a transformer can thus become more flexible.

Alternatively, the supply system can comprise a conveyor device having a shunt. The conveyor device can be a conveyor belt or even a roller belt, for example, via which a sheet-metal strip can be transported towards a feeder of the cutting device by its sheet-metal end. The shunt can form or interrupt a transport path to the cutting device so that optionally, depending on the placement of the shunt, one of the sheet-metal strips of the steel-strip rolls can be conveyed to the cutting device and there be inserted into the feeder. A major function of the shunt is no longer necessary if the cutting device draws in the respective sheet-metal strip via the feeder. The shunt can then already take up a different placement, for example for preparing supplying the further sheet-metal strip.

All in all, it is also possible to draw a sheet-metal strip from the cutting device by means of a reel head and to simultaneously supply a different sheet-metal strip to the cutting device and/or to unwind it from the steel-strip roll by means of the supply system. Thus, sheet-metal strips can be exchanged particularly quickly.

The reel system can comprise at least two reels. In this instance, a first reel head can be disposed on a first reel and a second reel head can be disposed on a second reel such that the first and the second reel head are disposed in a row relative to one another in the production direction upstream of the cutting device. The reel heads are then disposed one behind the other in the production direction. The respective reels can in turn comprise a plurality of reels heads which are disposed circumjacent to the reel. The use of two reels enables quickly exchanging a steel-strip roll, for example by simply rotating the reel, while a different steel-strip roll of the other reel is used in conjunction with the cutting device.

Furthermore, the reel system can comprise a reel having at least two reel heads disposed in a row. The reel system can then only comprise this one reel. Above all, it is also possible, however, for the reel system to have several reels having two reel heads disposed in a row. Thus, an even larger number of reel heads and/or steel-strip rolls can be disposed in a row upstream of the cutting device.

The reel can be realized so as to be rotatable around a vertical axis and comprise at least four reel heads disposed relative to one another at a 90° offset in relation to the vertical axis. By rotating the reel around the vertical axis, a steel-strip roll can be easily brought into a position upstream of the cutting device in the production direction. While using this steel-strip roll, it is possible to simultaneously exchange steel-strip rolls on the other reel heads of the reel to thus supply new material.

In the method according to the invention for producing transformer cores using a device, sheets of metal from which a transformer core is constructed are cut using a cutting device of the device, steel-strip rolls being disposed at respective reel heads of a reel of a reel system of the device, at least one steel-strip roll being disposed and unwound in a production direction of the cutting device, a sheet-metal strip of the steel-strip roll being supplied to the cutting device, steel-strip rolls being disposed on each of the at least two reel heads of the reel system, the steel-strip rolls being able to be unwound in the production direction of the cutting device and be disposed in a row relative to one another, sheet-metal ends of the sheet-metal strips of the steel-strip roll being supplied to the cutting device in an automated manner by means of a supply system. Regarding the advantages of the method according to the invention, the description of advantageous of the device according to the invention is referred to.

The device can comprise a control device by means of which supplying and/or drawing the sheet-metal ends to and/or from the cutting device can be controlled as a function of a shape of the transformer core to be produced. The control device can have means for data processing, such as a computer, and/or be a stored program control (SPC). The shape of the transformer core to be produced can be yielded from the desired physical properties and the measurements to be derived therefrom which can be determined or calculated using a core configurator for transformer cores. The core configurator can be, in particular, a software. In the same manner, measurements for sheets of metal of the transformer core can be derived from the core configurator and can be transmitted to the cutting device. Depending on the transformer core to be produced, the sheet of metal required for the respective sheets of metal for transformer cores or rather the corresponding sheet-metal strip can be supplied to the cutting device by means of the control device. Since the supply takes place in an automated manner and the steel-strip rolls are already disposed upstream of the cutting device, exchanging the sheet-metal strips can take place particularly quickly. Thus it is also possible to produce different transformer cores using one and the same device without costly retrofitting times.

Control commands can be transmitted to the control device by a control system of an installation for producing transformer cores as a function of component data describing a transformer core. The control system can comprise the core configurator, for example. It can be further intended for the control system to control the entire installation for producing transformer cores. The component data of a transformer core available in the control system can be converted to control commands which are transmitted to the control device. The control system can also have means for data processing, such as a computer with software.

A positioning of threading bolts on stacking tables, storage positions intended for the respective sheets of metal and disposed adjacent to a positioning system, and/or a cutting sequence of the cutting device for sheets of metal can be identified by means of the control system. It is then also possible, for example, to co-ordinate the different work stations of the installation for producing transformer cores with one another by means of the control system so that an optimal material flow having little processing time can be realized. The cutting frequency of a cutting device for sheets of metal can be adapted to an amount of sheets of metal in storage positions at a robot, for example, so that a sufficient amount of sheets of metal is always available in the storage positions. Furthermore, the stacking tables can be equipped with threading bolts in such a manner that certain kinds of transformer cores can be produced as a function of material flow. The control system can already determine or calculate the positions of the threading bolts on the positioning surface and transmit control commands to the control device for equipping a stacking table with threading bolts in the calculated positions. If steel-strip rolls required for producing a transformer core are no longer available, for example, the control system can initiate the production of other transformer cores for which enough material is available. The control system can transmit control commands to the control device to retrofit stacking tables and initiate producing and providing corresponding sheets of metal.

The reel can weigh the respective steel-strip roll using a weighing device and transmit weight data to the control system which can yield a strip length from the weight data and determine a use of the respective steel-strip using the cutting device. If the control system calculates the strip length from the weight data, a supply of a new steel-strip roll to the reel can be initiated by the control system when the strip length has approached a threshold value. Hence, a new steel-strip roll is already held at the ready on the reel after the steel-strip roll has been ultimately consumed, whereby idle time is prevented. Furthermore, due to the fact that the strip length is known it is possible to use the steel-strip rolls on the reel according to the respective strip length. The control system can calculate a number of sheets of metal for a transformer which can be produced using a steel-strip roll.

The sheet-metal ends can be threaded on and/or positioned on and/or removed from the cutting device by means of a multiaxial robot of the supply system. The robot can grapple a sheet-metal end directly from a steel-strip roll and supply it to a feeder of the cutting device.

Furthermore, it can be intended that after the removal of the sheet-metal end, the robot resupplies the sheet-metal end to the respective steel-strip roll during a winding of the steel-strip roll. A conveyor belt for the sheet-metal end can then be completely omitted.

The robot can separate a sheet-metal end from the steel-strip roll, glue it to the steel-strip roll, and/or affix an identification to the steel-strip roll. If the sheet-metal end is fastened to a steel-strip roll to prevent a winding of the steel-strip roll, the robot can remove the fastening or lift the sheet-metal end from the steel-strip roll and supply it to the cutting device. When resupplying the sheet-metal end to the steel-strip roll, the robot can glue the sheet-metal end to the steel-strip roll by means of a suitable device or fasten it in a different manner. It can be further intended for the robot to fasten an identification, such as a code, a barcode or a transponder, to the steel-strip roll. The identification on the steel-strip roll can also contain further information on the steel-strip roll, such as remaining strip length. This information can be processed by means of a control system of an installation.

In the scope of an alternative method progression, the sheet-metal ends can be threaded and/or positioned on the cutting device by means of a shunt of a conveyor belt of a conveyor device of the supply system. Advantageously, while a sheet-metal end is supplied via the shunt by means of the cutting device by unwinding the respective steel-strip roll, a further sheet-metal end can be supplied by winding the respective steel-strip roll. The supply can then take place via the correspondingly positioned shunt. Simultaneously, the further sheet-metal end still in the cutting device can be drawn from the cutting device and be wound onto the respective steel-strip roll by means of one of the reel heads. Since these processes can be carried out simultaneously, a particularly quick exchange of the sheet-metal strips becomes possible.

It can also be intended for the steel-strip rolls to each comprise a transponder, a transmitter-receiver unit of the reel system being able to identify the steel-strip rolls by means of the transponder. Consequently, an automated control can be carried out to ensure that the respective steel-strip rolls are always disposed on the reel heads intended therefor.

Further advantageous embodiments of the method can be derived from the descriptions of features of the dependent claims referring back to claim 1.

In the following different embodiments of the invention are further described with reference to the attached drawings.

FIG. 1 shows a schematic view of an installation for producing transformer cores;

FIG. 2 shows a top view of a first embodiment of a reel system;

FIG. 3 shows a lateral view of the reel system from FIG. 2 in a first operating position;

FIG. 4 shows a lateral view of the reel system from FIG. 2 in a second operating position;

FIG. 5 shows a top view of a second embodiment of a reel system;

FIG. 6 shows a lateral view of the reel system from FIG. 5.

FIG. 1 shows a schematic illustration of an installation 10 having a device 11 for producing transformer cores 12. Installation 10 comprises a control system 13 which serves for controlling installation 10. Component data 14 describing transformer cores 12 are processed using control system 13 by means of a so-called core configurator 15 so sheets of metal 16 from which transformer core 12 is constructed are calculated using their measurements. Control system 13 transmits control commands and/or data for producing transformer core 12 to a control device 17 which then initiates producing transformer core 12 using corresponding control commands.

Device 11 comprises among other elements a number of stacking tables 18 having a retaining system 19 for collecting sheets of metal 16. Retaining system 19 comprises at least two threading bolts 20 and, in this shown embodiment, substructions 21 for placing sheets of metal 16. Sheets of metal 16 are realized having bores not illustrated in this instance and are placed and/or inserted on threading bolts 20. Sheets of metal 16 are placed on threading bolts 20 or rather on stacking table 18 by means of a robot 22 of a robot system 23. Threading bolts 20 are also positioned on a positioning surface 26 of stacking table 18 by means of a robot 24 of a positioning system 25. Positioning surface 26 is flat so a free positioning and a location-independent fastening of threading bolts 20 on positioning surface 26 can be effected according to the specifications of control system 13. Threading bolts 20 are stored in a magazine 27 and are disposed on or removed from positioning surface 26 by means of robot 24. For this purpose, stacking table 18 is transported by means of a self-propelling cart 28. Cart 28 transports stacking table 18 to illustrated robot systems 23 at which stacking table 18 is equipped with sheets of metal 16 or rather sheets of metal 16 are stacked to construct transformer core 12. After transformer core 12 has been stacked, stacking table 18 is transported away from robot system 23 by cart 28.

A number of sheets of metal 16 is supplied to robot systems 23 from a cutting device 30 by means of a conveyor device 29 and are stacked adjacent to respective robot 22 in two storage positions 31 for different sheets of metal 16 in each instance. Robot 22 and/or storage position 31 is/are also controlled by means of control device 17. Robot 22 grapples sheets of metal 16 from respective storage positions 31 and positions them on threading bolts 20 on stacking table 18 until transformer core 12 is constructed. Robot 22 can be displaced above conveyor device 29 so that robot 22 can equip four stacking tables 18 with sheets of metal 16 simultaneously.

Only schematically illustrated cutting device 30 serves for cutting sheets of metal 16 and is controlled by control device 17. In cutting device 30, not-illustrated sheet-metal strips are cut such that sheets of metal 16 are yielded. Not-illustrated sheet-metal strips are supplied from steel-strip rolls to cutting device 30.

A synopsis of FIGS. 2 to 4 shows a reel system 32 on a cutting device 33. Reel system 32 comprises a first reel 34 and a second reel 35, first reel 34 comprising reel heads 36 having steel-strip rolls 37 and second reel 35 comprising reel heads 38 having steel-strip rolls 39. Reels 34 and 35 are each realized so as to be rotatable around a vertical axis 40 or 41, respectively, and the respective reel heads 36 and 38 are disposed at a 90° offset relative to one another on respective reel 34 or 35. Respective, only indicated sheet-metal strips 42 and 43 of reels 34 or 35, respectively, can be supplied to an introduction 44 of a not-illustrated feeder of cutting device 33 in a production direction marked by arrow 45. Steel-strip rolls 37 disposed in production direction are positioned in particular in a row relative to one another upstream of introduction 44. Below these steel-strip rolls 37 and 39 is a supply system 46 which is made up of a conveyor device 47 having a shunt 48. Conveyor device 47 comprises a conveyor belt 49 having a strip centering 55 via which sheet-metal strip 42 or 43 can be conveyed in the direction of introduction 44.

A first operating position of shunt 48 can be seen in FIG. 3, sheet-metal strip 43 being able to be supplied directly into introduction 44 via shunt 48. A same kind of supply can generally take place for strip 42 by means of shunt 48.

According to FIG. 4, shunt 48 which is also realized as a kind of conveyor belt 51 is positioned such in a first operating position that sheet-metal strip 43 passes through a horizontal shaft 52 in loops in order to eliminate bending stresses in sheet-metal strip 43.

Reel system 53 shown in FIGS. 5 and 6 is also disposed upstream of a cutting device 54 and realized solely from a reel 55. Reel 55 comprises a total of eight reel heads 56 each having different steel-strip rolls 57. At least two reel heads 56 are always disposed in a row relative to one another in a production direction of cutting device 54 indicated by arrow 58. In this instance, reel 55 or rather reel heads 56 can also be rotated around a vertical axis 59. A supply system 60 is realized by a multiaxial robot 61. Robot 61 comprises a robot arm 62 at whose end 63 a grappling device 64 is disposed for handling not-further-illustrated strip ends of sheet-metal strips 65 and 66 of steel-strip rolls 57. Robot 61 can grapple the respective strip ends on the sheet-metal strips 65 or 66 and supply them to an introduction 67 of cutting device 54. Furthermore, a sheet-metal end of a sheet-metal strip 65 or 66 can be resupplied to a steel-strip roll 57 using robot 61 if sheet-metal strip 65 or 66 is drawn from cutting device 54. 

1. A device (11) for producing transformer cores (12), the device comprising a cutting device (30, 33, 54) for cutting sheets of metal (16) from which a transformer core is constructed and comprising a reel system (32, 53) having a reel (34, 35, 55), the reel comprising reel heads (36, 38, 56) each having steel-strip rolls (37, 39, 57), at least one steel-strip roll being disposed so as to be able to be unwound in a production direction of the cutting device, a sheet-metal strip (42, 43, 65, 66) of the steel-strip roll being supplied to the cutting device, characterized in that the reel system comprises at least two reel heads each having a steel-strip roll disposed thereon, the steel-strip roll being disposed so as to be able to be unwound in the production direction of the cutting device and being disposed in a row relative to one another, the device comprising a supply system (46, 60) by means of which sheet-metal ends of the sheet-metal strips of the steel-strip rolls being supplied to the cutting device in an automated manner.
 2. The device according to claim 1, characterized in that the supply system (60) comprises a multiaxial robot (61).
 3. The device according to claim 1, characterized in that the supply system (46) comprises a conveyor device (47) having a shunt (48).
 4. The device according to claim 1, characterized in that the reel system (32) has at least two reels (34, 35).
 5. The device according to claim 1, characterized in that the reel system (53) has a reel (55) having at least two reel heads (36, 38, 56) disposed in a row.
 6. The device according to claim 1, characterized in that the reel (34, 35, 55) is realized so as to be rotatable around a vertical axis (40, 41, 59) and has at least four reel heads (36, 38, 56) disposed at a 90° offset relative to one another in relation to the vertical axis.
 7. A method for producing transformer cores (12) using a device (11), sheets of metal (16) from which a transformer core is constructed being cut using a cutting device (30, 33, 54) of the device, steel-strip rolls (37, 39, 57) being disposed on each reel head (36, 38, 56) of a reel (34, 35, 55) of a reel system (32, 53) of the device, at least one steel-strip roll being disposed and unwound in a production direction of the cutting device, a sheet-metal strip (42, 43, 65, 66) of the steel-strip roll being supplied to the cutting device, characterized in that steel-strip rolls are disposed on at least two reel heads of the reel system in each instance, the steel-strip rolls being able to be unwound in the production direction of the cutting device and being disposed in a row relative to one another, sheet-metal ends of the sheet-metal strips of the steel-strip rolls being supplied to the cutting device in an automated manner by means of a supply system (46, 60).
 8. The method according to claim 7, characterized in that the device comprises a control device (17) by means of which supplying and/or drawing the sheet-metal ends to and/or from the cutting device (30, 33, 54) is controlled as a function of a shape of the transformer core (12) to be produced.
 9. The method according to claim 8, characterized in that control commands are transmitted to the control device (17) from a control system (23) of an installation (10) for producing transformer cores (12) as a function of component data describing a transformer core.
 10. The method according to claim 9, characterized in that the control system (23) is used to identify a positioning of threading bolts (20) and/or sheet-metal abutments on stacking tables (18); storage positions (31) adjacent to a positioning system (25) and intended for the respective sheets of metal (16); and/or a cutting sequence of the cutting device (30, 33, 54) for sheets of metal.
 11. The method according to claim 9, characterized in that the reel (34, 35, 55) weighs the respective steel-strip rolls (37, 39, 57) using a weighing device and transmits weight data to the control system (23), the control system deriving a strip length from the weight data and determining a use of the respective steel-strip roll using the cutting device (30, 33, 54).
 12. The method according to claim 7, characterized in that the sheet-metal ends are threaded on and/or removed from the cutting device (30, 54) by means of a multiaxial robot (61) of the supply system (60).
 13. The method according to claim 12, characterized in that after removing the sheet-metal end, the robot (61) resupplies the sheet-metal end to the respective steel-strip roll (57) during a winding of the steel-strip roll.
 14. The method according to claim 12, characterized in that the robot (61) separates a sheet-metal end from the steel-strip roll (57), glues it to the steel-strip roll and/or affixes an identification to the steel-strip roll.
 15. The method according to claim 7, characterized in that the sheet-metal ends are threaded on the cutting device (30, 54) by means of a shunt (48) of a conveyor belt (49, 51) of a conveyor device (47) of the supply system (46).
 16. The method according to claim 15, characterized in that while a sheet-metal end is supplied to the cutting device (30, 54) via the shunt (48) by unwinding the respective steel-strip roll (57), a further sheet-metal end is resupplied to the respective steel-strip roll by winding.
 17. The method according to claim 7, characterized in that the steel-strip rolls (37, 39, 57) each have a transponder, a transmitter-receiver unit of the reel system (32, 53) identifying the steel-strip rolls by means of the transponder. 